Contamination of subsurface soil and its environmental impact has been the subject of considerable public attention and has caused much concern with respect to the storage and disposal of materials such as waste with the potential for contamination. When exposed to soil, it is common for such contaminating or hazardous materials to lodge in the interstices or pore space of the soil, or to become part of the soil solutions, which can be generally defined as the interstitial water in the soil together with solutes and dissolved gases. The frequent lack of detectability by sight of such hazardous materials and subsurface soil solutions can mean that the problems caused by such hazardous materials often do not manifest themselves until the situation has reached a critical point. The need exists, therefore, for methods and apparatuses for obtaining samples of liquid and gas from subsurface soil in order to subsequently analyze some samples for the possible presence of hazardous materials. Even where no concern for hazardous materials exists, it is important to be able to obtain samples of liquid and gas from subsurface soil for various other scientific purposes.
Various devices exist within the prior art pertaining to sampling of subsurface soil. Some such devices are for in situ collection of representative soil solution samples, and these are sometimes called lysimeters. One type of lysimeter is referred to as a suction lysimeter and utilizes a receptacle implanted in the earth having a conduit extending from the receptacle to the earth's surface and utilizing a vacuum pull through the conduit to draw soil solution samples through a filter into the receptacle and through the conduit to the earth's surface.
U.S. Pat. No. 4,759,227 to Timmons teaches an apparatus and process disclosing a lysimeter utilizing a filter section which is a rigid, porous, fluoroplastic through which moisture from soil surrounding the lysimeter can pass into a chamber of the lysimeter.
U.S. Pat. No. 5,035,149 to Wierenga discloses a soil solution sampler of the lysimeter type wherein the sampler comprises a receptacle comprised of a first tube formed from porous stainless steel to permit flow of solution through its walls, and a second tube formed of non-porous stainless steel joins to the end of the first tube. An air conduit for applying a vacuum to the interior of the receptacle and for applying positive pressure to the interior of the receptacle is provided and extends into the receptacle into the earth's surface. The sampler has a sample transfer conduit for conveying samples from the receptacle to the surface.
U.S. Pat. No. 3,930,754 to Mogg et al. discloses a portable water sampling apparatus for sampling water from a well wherein the apparatus comprises a wheeled hose reel cart which supports a long length of plastic hose or tubing with the tubing having a small diameter length of inner tubing telescoped inside itself throughout most of its length. The inner tubing passes through the wall of the outer tubing near the upper end thereof and is connected to a pressurized cylinder of gas. Admission of gas to the inner tube at its upper end when the lower ends of the tube are submerged beneath the water level in a well will force water up through an annular space between the tubes and out the upper end of the outer tube for collection. The channeled plug at the bottom of the tubes is used to prevent the tubes from collapsing and help maintain the tubes straight and together as they are lowered into the well. The channeled plug also provides a partial support for a weight to hang from the bottom of the tubes for aid in placement.
U.S. Pat. No. 4,160,622 to Colburn also discloses a portable water sampling apparatus for sampling water in a well. The apparatus of Colburn comprises a wheeled hose reel cart supporting a long length of coextruded plastic hose or tubing with the coextrusion comprising a small diameter portion of tubing attached by a web to a large diameter portion of tubing and with the small diameter tubing being connected to a pressurized cylinder of gas. A generally j-shaped piece of metal tubing is utilized and projects from the inside of the smaller tubing, which it fictionally engages, into the center of the larger tubing at the lower end thereof. When the lower ends of the tubes are well submerged beneath the water level in a well, admission of gas to the smaller tube at its upper end forces water entering the larger tubing in the annular space surrounding the metal tubing up through the larger tube and out the upper end of the larger tube for collection.
U.S. Pat. No. 3,722,589 to Smith et al. discloses a method for performing production testing of wells comprising the steps of introducing into and withdrawing from a well a small diameter tubing by an injector apparatus. While in the well, the small diameter tubing is hung in the well with its lower end adjacent a formation to be tested, and gas is injected through the tubing to lift a layer of uncontaminated reservoir fluid to the surface continued gas injection accomplishes formation flow characteristic evaluation.
U.S. Pat. No. 5,010,776 to Lucero et al. discloses an environmental contamination detection and analyzing system and method. The method and system for detecting environmental contamination according to Lucero et al. utilizes a test probe located in a medium wherein the probe is adapted to collect a fluid sample from the medium for determining the presence of a contaminant having a vapor pressure. Pneumatic communication lines extend from a test point and connect to the probe and a detector/analyzer is connected to the distal end of the communication lines of the probe. A fluid sample is taken into the probe and transported in the pneumatic communication lines by a carrier gas to the detector/analyzer for analysis of the contaminant.
Another method and apparatus for obtaining samples from the earth is disclosed in U.S. Pat. No. 2,214,551 to Edwards.
Despite the prior art references, there exists room for improvement in the art.